The relative survival and cure fraction of gastric cancer estimated through flexible parametric models using data from population-based cancer registration during 2003-2012 in Linzhou, China

Trends of stomach cancer survival: A systematic review of survival rates from population-based cancer registration

OBJECTIVES

We aimed to describe the pattern and time trends of survival from stomach cancer worldwide from population-based cancer registers.

METHODS

A systematic search of PubMed, Web of Science, EMBASE, SEER and SinoMed for articles published up to 31 December 2020 was conducted. All eligible survival analyses of stomach cancer were collected and evaluated by countries or regions, periods, sex and age groups.

RESULTS

Our review included 76 articles on stomach cancer survival rates and found that these rates had improved globally with time, although this increase was unremarkable. The highest 5-year survival rate of 72.1% was observed in Japan (2004-2007). The 5-year relative and net survival, rates were relatively high in Korea and Japan, while they were fairly poor in Africa and India. Sex-specific survival rates were higher in women than in men in America, Europe and Oceania, whereas they were relatively low in Asia. The poorest age-specific 5-year relative and net survival rates were observed in patients aged over 75 years.

CONCLUSIONS

Over the past decades, patient prognosis of stomach cancer has gradually improved worldwide and survival rates in developed regions were higher than those in developing regions. White men and Asian women had a poorer survival than white women and Asian men. Younger patients had better survival rates than those aged over 75 years globally.

Spatiotemporal Hotspots of Study Areas in Research of Gastric Cancer in China Based on Web-Crawled Literature

Gastric cancer is a common malignancy worldwide and poses a serious threat to human public health. The difficulty in obtaining epidemiological data limits the development of cross-disciplinary related research. In this study, 99,364 publications on gastric cancer from 1991 to 2019 were obtained using web-crawler technology, and a technical framework for extracting toponyms from these publications was constructed to analyze spatiotemporal hotspots of study areas in gastric cancer research in China. The results showed the following: (1) The accuracy of toponym extraction was greatly improved after eliminating the systematic exclusion words and adding historical toponyms, with a precision of 95.31% and a recall of 94.86%. (2) Gastric cancer research (GCR) and gastric cancer research with toponyms (GCRWT) are attracting increasing amounts of attention. The amount of GCR results published in Chinese and English is gradually leveling off, and the imbalance between those of GCRWT is gradually widening. (3) The spatial distribution of gastric cancer research in China is uneven, and the hotspots are mainly located in the eastern coastal areas. There were huge advances in gastric cancer research at the province/city/county scale in Eastern China, while the central region has only increased research at the county scale. We suggest that gastric cancer research should pay more attention to the central region, which has the highest gastric cancer incidence/mortality. This study provides important clues for research on and investigations of gastric cancer.

The relative survival and cure fraction of gastric cancer estimated through flexible parametric models using data from population-based cancer registration during 2003-2012 in Linzhou, China

PURPOSE

The proportion of cured gastric cancer patients has drawn the attention of patients, physicians, and healthcare providers after comprehensive prevention and control measures were carried out for several years. Therefore, the relative survival and cure fraction were estimated in our study.

METHODS

Population-based cancer registration data were used to estimate survival and cure fraction. A total of 7585 gastric cancer cases (ICD10:C16.0 ~ C16.9) were extracted and included in the final analysis. Cases were diagnosed in 2003-2012 and followed until the end of 2017. Relative survival was calculated as the ratio between the observed survival through the life-table method. The expected survival was estimated by the Ederer II method. The cure fraction was estimated using flexible parametric cure models stratified by age and calendar period when the cases were diagnosed.

RESULTS

The 5-year relative survival of cardia gastric cancer increased with the calendar period of 2003-2004, 2005-2006, 2007-2008, 2009-2010, and 2011-2012 (27.5%, 28.3%, 33.5%, 38.2%, and 46.8%, respectively). The increasing trend along with the calendar periods was also observed in cure proportion of cardia gastric cancer (24.8%, 25.2%, 31.7%, 36.0%, and 43.1%, respectively). Notable improvement of cure proportion was observed in the period of 2011-2012, compared with the initial period of 2003-2004. There was an improvement of 79.8% among all gastric cancer subjects, and it was 74.1% and 55.7% in cardia gastric and noncardia gastric cancer subjects, respectively. The median survival of "uncured" patients showed no significant improvement along with the calendar periods in all age groups.

CONCLUSIONS

Notable improvement of gastric cancer relative survival and cure proportion was observed in Linzhou during 2003-2012.